1. Technical Field
The present invention relates generally to an improved distributed data processing system and in particular to a method and apparatus for providing users access to applications at different clients within the distributed data processing system.
2. Description of Related Art
In distributed data processing systems, the client-server model is a well-known environment. In this model, the user of a computer utilizes a “client” system. The client system runs any of a number of computer operating systems to manage the basic functions that users execute, such as accessing files, executing programs, and system administration, as well as to serve as the base against which programs are written. Well-known client operating systems include Microsoft Windows 3.1, Windows for Workgroups, Windows 95, IBM® OS/2® Warp, Apple Macintosh, DOS, many variations of UNIX, and Microsoft Windows NT. The client system serves as the user's workstation, and it may execute programs as well as store some user data.
The server system can also run any of a number of computer operating systems. Well-known server operating systems include, for example, Novell NetWare, IBM OS/2 Warp Server, IBM AS/400®, Microsoft Windows NT, and many variations of OSF UNIX. The server system is accessed by the client system for specific functions. The functions include, but are not limited to, storage and retrieval of data, storage and execution of applications, and storage of and access to user information.
The client-server model continues to evolve to meet the need for distributed resources. As personal computers have gained more functionality and reliability, end-users have improved their productivity through the use of a variety of distributed computing resources. While some enterprise data and legacy applications continue to be placed on reliable mainframe platforms, the need for distributed enterprise access to large numbers of applications and large amounts of data continues to grow.
Operating systems and computing hardware platforms have proliferated, and each combination of computer hardware and software addresses the need for a variety of price, performance, legacy compatibility, and features. Traditional PCs, such as desktop and laptop PCs, are designed to offer highly sophisticated end-user environments. The installation of workgroup computing software and complete application suites requires a computer with significant local storage and local networking capabilities. Network computers (NCs), on the other hand, offer a different type of versatility as they may provide limited access to Java™ and Windows™ based applications. NCs are typically implemented with only a general purpose processor, a system memory, and a communications port. Therefore, NCs typically rely upon network access to provide dynamic, non-volatile data storage capability.
Each of the various implementations of the client-server model has advantages and disadvantages. Networked PCs have the advantage of providing extensive flexibility. In order to accommodate their need for computing resources, users may add peripherals and software applications directly to a PC, while a network administrator may provide other resources on the network for many users in a common fashion. The disadvantages include the immense burden placed on a network or system administrator in ensuring that the various PCs retain some semblance of a standard configuration. Many operating systems provide various levels of system administration capabilities for accomplishing such administrative tasks. However, as users become more technically sophisticated through everyday use of various computing devices, users demand more options in their access to data and to computing resources. For example, people who travel extensively or work at various locations may rely on the ability to have access to a common set of applications wherever they are located. Enormous costs and amounts of time may be spent in accommodating user preferences while pursuing corporate directives for the use of standard configurations.
Industry standards have been developed for both critical and common functions to aid in the implementation of a system containing different types of client systems accessing different types of server systems. The use of these standards on the client and server afford users the opportunity to carry out functions in a consistent manner on a variety of common client and server operating systems, thereby reducing administrative costs. For example, one of the activities that has been standardized is the “authentication” of users. Authentication refers to the process in which a user is validated as being able to complete a logon and/or access a system. Standard protocols have been defined within the X/Open Server Message Block (SMB) specification and the Open Systems Foundation (OSF) Distributed Computing Environment (DCE) specification. While many products and operating systems have been developed that utilize standard protocols, not all products have used the standards. Hence, enterprises confront the difficult challenge of cost-effectively maintaining system administrative knowledge of enterprise-wide computer configurations while allowing some amount of user-specific configuration flexibility within a variety of operating systems that use non-standard protocols and data file formats.
With respect to the use of non-standard protocols, Windows 95, Windows 98 and Windows NT are such an example. With these operating systems, updates to the operating system including configuration changes, operating system settings, device drivers, and installation of applications all use the registry to store and retrieve information from values within the registry. The registry contains information that is partitioned into two sections. General system information is found in one section and user specific information is found in the other section of the registry. Updates to the registries in the operating systems, however, only can be made using Microsoft Windows application program interfaces (APIs). As a result, distributed data processing systems in which non-Windows servers are present, these servers are unable to initiate and incorporate changes to the registry.
Thus, it would be advantageous to have an improved method and apparatus for providing user access to applications at different clients within the distributed data processing system.